Mysqli: how to make a limit select for a pair of IN values?

Question

MySQL

There is a table contactswith fields id|city_id|category_id|email
Now the query is:

"SELECT (id,email) FROM contacts WHERE city_id IN (".implode(',', $arrCity).") AND category_id IN (".implode(',', $arrCategory).")"

How can I select 10 entries for each city->category pair?

Answer 1

IMHO, only via UNION subqueries for each pair

Answer 2

I agree with Rsa97, make 2 requests with limits, and unite them with UNION.